1. Field of the Invention
The present invention relates to a transmission lubricating structure mounted to a driving source such as an engine.
2. Description of the Related Art
Japanese Laid-Open Patent Application Publication No. 2009-24618 discloses a transmission including a gear pair composed of a drive gear and a driven gear. In this transmission, a lubricating fluid adhering to a crank web is scattered and fed to the gears of the gear pair, by a centrifugal force generated during rotation of the crank web. A portion of the lubricating fluid scattered by the centrifugal force adheres to a lateral wall of a crankcase. This lubricating fluid is dropped from a protrusion provided on the lateral wall and is fed to the gears of the gear pair. In this transmission, the lubricating fluid is fed to the gears of the gear pair by scattering it by the centrifugal force, or dropping it from the protrusion provided on the lateral wall. In this method, it is difficult to sufficiently feed the lubricating fluid to a tooth of the drive gear and a tooth of the driven gear, which teeth are in engagement (in mesh). Especially in a case where an engine output is great, abrasion of the gears of the gear pair tends to occur.